Joe, to donate from the US, you should use the drop-down menu next to the "Donate" button to set US Dollars (USD) and then you can select United States (and the selections will change to City, State ...instead of County of Europe). It's not about 'letting' you... just need to make the currency selection first.

Admin needs an account username/password (sent to xndevel@gmail.com ...not posted here) in order to write a -custom- script for various ISP providers of the world. (You can change the password after the script is written.)